"free radical." YourDictionary, n.d. Web. 14 September 2018. <http://www.yourdictionary.com/free-radical>.
free radical. (n.d.). Retrieved September 14th, 2018, from http://www.yourdictionary.com/free-radical
An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.